Fluid flow sensors & leak detection systems

Abstract

Described herein is a method for determining the presence of a leakage in a fluid system, for example, a domestic plumbing system. The method comprises measuring vibration spectra relating to fluid flow in the system and comparing the measured spectra with reference spectra to determine the presence of a leakage. A simple sensor ( 12 ) is attached to a pipe ( 10 ) for measuring the vibration and is connected to a processing unit ( 14 ) via wired connection ( 18 ). The sensor ( 12 ) may also be provided with an amplifier/buffer ( 16 ) and a battery pack ( 20 ). The sensor is used in a leakage detection system which is also described.

1 . A method of determining the presence of a leakage from a fluid system comprising sensing the vibrations induced by passage of the fluid through the leakages; segmenting the sensed vibrations into at least two spectral bands; comparing the amplitudes of the spectral bands with predetermined values to determine flow rate.  
     
     
         2 . A method according to  claim 1 , further comprising attaching a sensor to the fluid system to obtain data therefrom indicative of fluid flow therethrough.  
     
     
         3 . A method according to  claim 2 , wherein the sensor includes a piezo-electric material.  
     
     
         4 . A method according to  claim 3 , wherein the sensor includes a PVDF film.  
     
     
         5 . A method according to  claim 2 , wherein the sensor comprises one of a strain gauge, geophone or hydrophone.  
     
     
         6 . A method of determining leakage from a fluid system substantially as hereinbefore described with reference to the accompanying drawings.  
     
     
         7 . Apparatus for determining the presence of a leakage from a fluid system comprising a vibration sensor for sensing vibrations induced by passage of the fluid through the leakages, a segmentor for segmenting the sensed vibrations into at least two spectral bands, a comparitor for comparing the amplitudes of the spectral bands with predetermined values to determine flow rate.  
     
     
         8 . Apparatus as claimed in  claim 7  wherein the sensor includes a piezo-electric material.  
     
     
         9 . Apparatus as claimed in  claim 8  wherein the sensor includes a PVDF film.  
     
     
         10 . Apparatus as claimed in  claim 8  wherein the sensor comprises one of a train gauge, geophone or hydrophone.  
     
     
         11 . Apparatus for determining leakage from a fluid system substantially as hereinbefore described with reference to the drawings.  
     
     
         12 . A leakage detection system for use in a fluid carrying system which leakage detection system comprising: 
 at least one sensor mountable to the exterior of a pipe of the fluid carrying system which sensor comprising a vibration sensor for measuring vibrations in the pipe caused by fluid flow in the pipe and to provide output signals indicative of the vibrations; and    a processing unit for receiving signals from at least one sensor and for comparing the received signals with reference data to determine the presence of a leak.    
     
     
         13 . A leakage detection system as claimed in  claim 12  including apparatus as claimed in  claims 7  to  11 .  
     
     
         14 . A leakage detection system substantially as hereinbefore described with reference to and as illustrated by the drawings.